Visible liquid fuse switch



Oct. 11, 1932.

| J. SJOBERG VISIBLE LIQUID FUSE SWITCH Filed Jan. 22, 1950 2 Sheets-Sheet 1 INVENTOR 1.. fjoaaRc. BY Willis/u ATTORNEYS 2 Sheets-Sheet 2 L. J. SJOBERG VISIBLE LIQUID FUSE SWITCH Filed Jan. 22.

Oct. 11, 1932.,

INVENTOR L'.J. SJOBERG ATTORNEYS w @WT Patented Oct. 11, 1932 LEO JAMES SJOBEBIG, O1 LOSANGELES, CALIFORNIA, ASSIGNOR T LEO J. SJ'OBERG" EQNT OFFIQE AND WALIJIER-B. DENURE; TRUSTEES, OF IiOS' ANGELES, CAIIFORNIK.

VISIBIi-E"LIQUID FUSE SWITCH inventionppertains-to a visible liquid fuse switchzandais of: a type suitable for high voltage electric currents.

Oneiof the: features and-objects of-my invention is itheqconstructioniof a. fuse switch using: "liquid: which. may be. visible in that the interior of-the'-.switoh may be I observed form the casing orihousingifor the-switch having the oilstherein, off glassioraother trans parentsmaterial.

Another feature ofihavi-ng. the transp arent container for the-switchbis-that the position.

ofathe con't'aots-iandrthe conditionofxthe fuse may also be examined without opening the switchondisconnectingtheidevice. 'Dhisfactor. of! allowing a direct-observation. of the position wot-the icontaotssavoids the necessity of having markings-another devices to-indicate when the switch is .in the closed :oropen position and therefore eliminatesthe danger 351' of .anincorreotereadingz.

Anothersohjeot. :of my invention is a .pro vision for. takingmare of-the flash 'or. explosion which sometimes: occurs; in oil switches fromdevelopment-ofgas, inthat a. form of $5 safety; valve is used which allows the gas to blow out of' 'the container or-recept-acle and thus .prevents injuryto theswitch housing and the switch construction mounted internally therein.

furtherlobject ofimy invention is the provision of a" simplified construction forsecuring-the switch housing withthe switch there in; to a supporting structure, this being by meansofa slidab'le connectionand avoiding lfi 'the necessity for-fastening the switch housing onbody to" the supporting structure by directfastenersz' Another feature 'and'object of my inventionis the constructionof a cap with a-switch body with a core having contacts connected to the cap, whereby the core is removed from the housing or container by rotating and lifting the cap and-also wherein when the core and the cap have once been connected thev cannot be disconnected except by breakage of eitherthe core or the cap thus assuring the correct assembly of these elements ofthe switch and alsoassuring that thepart which.

has deteriorated or is otherwise not fit for ser-v1ce,-must be replaced by a new element.

Another feature of my invention is the construction for connectingtthe :lead-in-wi res and the leads fromthese wires intothe container withthe type ofcontacts used therein. The leads to'the exterior wires arecarried upwardly in upwardly'and.downwardly extending passages, so that when thelead-in wires are once connected, there is no danger ofa short clrcult between such wlres. The

fixed contacts-in the container areattached to conductlng screws or bolts extending throughthe walls-of the container andthese are engaged by the contacts on the core,

which core is connected to the cap and after insertion must be rotated tobringthe contacts on the core into engagement-withrthe fixed contacts in the container.

Another feature of my lnventlon mcludes the resillent mounting of the contacts on the core and the mountin and construction of the fuse connecting these latter contacts.-

My invention willbe understood from the accompanyingdrawings,.in which,

Fig. 1. is a side elevation taken in the direction of the arrow 1 of Fig. 2.;

Fig. 2 is an elevation taken in the direction of'the arrow 2 of Fig.

Fig.3 is aplan taken in the direction of the arrow 3 .of Fig. 1;

Fig. 4 is a vertical section taken on the line 4-4 of Fig. 2 in the direction of the arrows;

Fig. 5 is asection onthe line 55 of Fig. 1, taken in the direction ofthe arrows part of-the core being shown in elevation;

Fig. 6 is a transverse section on the line 6-6 of Fig. 4. in the direction ofthe arrows;

Fig. 7 is a section on the line 7-7. of Fig. 1in the direction of the arrows;

In the construction of my invention-I il lustrate a cross bar 11 such as is in common use in electric Wiring systems, to support lead wires and switch elements. To this cross bar there is attached a holder 12, this having an upper strap 13 extending over the bar 11 with a downwardly extending end 14 and a screw 15 extending through this latter end. The face of the holder 16 is provided with a downwardly extending wide tapered slot 17 and there is a marginal rim 18 to engage part of the container as herein detailed. The marginal portions of the slot are indicated at 19 and the back portion of the slot 20 is back to the vertical face of the bar 11 (note Figs. 1, 2, 3 and 5.)

A container 21, preferably formed of transparent glass is indicated as having a cylindrical body structure 22 and a horizontal base 23 with a rounded rim 24 at the top. At

the back of the container there'is a downwardly tapered wide projection 25 and this has a side portion 26 extending beyond the main portion of the body of the container and has downwardly and inwardly sloping side edges 27. There is a slight concave back surface 28 and front vertical surface 29 and also parallel to these, flat back surfaces 30.

The fiat back surfaces 30 fit against the vertical surface 20 of the holder. The downwardly tapered side edges 27 fit in the portions 19 of the holder and the rim 18 of the holderengages the surface 29 of the container.

The container has enlarged integral bosses 1 on opposite sides. Each of these has a horizontal enlarged opening 32 and concentric therewith there is a smaller opening 33 extending through the container to the inner substantially cylindrical surface 34. Extending downwardly from this horizontal opening there is a downwardly sloping opening 35. In addition preferably on the rear side of the container there is. another enlarged boss 36. This is illustrated as having a bore 37 therethrough and an outer enlarged section 38 of this bore forming a valve seat 39 at the junction between the two sections of the bores. These bores preferably slope slightly downwardly. There is a vertical slot 40 on the inside of the container immediately behind the bore 37 and in this slot there is fitted a small pin or bar 41. This is utilized to hold a valve plug 42 against its seat 39 in the bore 37, there being a tension spring 43 connecting the small rod and the lug. This is utilized as an explosion relief valve. For the purpose of strengthening the container there is a slight molding 44 joining the bosses 31 and 36.

Bolts 45 are illustrated as being fitted in the reduced opening 33. These bolts pass through openings in the fixed contact plates 46 on the inside of the container, the plates fitting in vertical grooves 47 and the bolts pass through cup-shaped insulators 48 and are threaded into nuts 49 in these insulators. Packing washers 50 are positioned between the glass of the container and the head 51 of the bolts. There is a vertical perforation 52 through the heads and a small bolt 53 is threaded through the opening 54 in the heads. This bolt has a head 55 with a kerf therein which engages a small pipe section 56. The inner end of the bolt and the rim of the pipe engage the scraped end 57 of the lead-in Wires; such wires being led through the inclined opening 35 and the insulation 58 filling these openings. (Note Figs. 4 and 7.) The container is provided with a glass top 59 and this top has a hand grip end 60 with an annular groove 61 to accommodate the operators fingers and has a skirt 62, there being a bearing surface 63 on the inside of the skirt to fit against the rounded rim 24 of the top of the container.

A plug section 64 extends downwardly in the container and has adove-tailed slot 65 extending from one'side to the other. The plug is preferably circular and is illustrated as being slightly tapered downwardly. There is also a dowel socket 66 extending upwardly in thecap and this cap is preferably made of glass.

The core 67 has a cylindrical upper portion 68 and above this there is a transverse projection 69 of a dove-tailed formation to fit in the dove-tailed slot 65 of the cap. There is a socket 70 in the upper portion of the core in which is fitted a slidable dowel 71 outwardly pressed by a spring 72. The core and the cap are assembled by depressing the dowel 71 and slipping the dovetailed end of the core in the groove of thecap until the dowel is pressed by the spring upwardly into the dowel socket 66, whence these parts are thence secured together and there is no way of disconnecting them except by breakage, either of the neck of the core or of the cap.

The lower part of the core 73 is flattened and has a plurality of shallow sockets 74 on the edges and also a plurality of transverse openings 75 with cored holes 76 connecting the sockets 74 and the holes 75. Fitted in these holes 76 there are slidable pins 77, the pins extending in the openings 74 and having cotter pins 78 therethrough to limit the motion of the pins 77. These pins have heads 78 on the outside and attached to these heads there are the movable contact plates 79; the pins and-the plates being The core has a downward projection 82 and the contact plates 79 also have downwardly extending ends 83 which are preferably reduced in width and to these ends there is connected a flexible fuse 84; the fuse being secured by clamping bolts 85 to the ends 83 of the movable contacts. After assembling the core and the cap, the core may be inserted in the container, turned in such a position so that the least dimension fits between the in side nuts 49 and the cupped insulators 18 on the bolts 45 and when so introduced the contact plates 7 9 on the core are out of contact with the fixed contact plates 46 on the walls of the container. WV hen it is desired to close the switch after introducing of the insulating oil, the level of which is indicated by the numeral 86, the cap is rotated one-quarter of a turn, thus carrying the core with its contact plates and the rim section 81 of these lat-es first contacts with the fixed plates 46. The further rotation causes a depression of the movable plates 7 9, the pins 77 having a sliding motion until the plates are brought into flat contacting position as shown in Figs. t and 6, thus making the full circuit position. The opening of the switch is merely done by rotating the cap one-quarter of a turn from the closed position.

It will be seen by my construction that on account of using a transparent container that the position of the switch can be always cbserved, whether this is in the open or closed circuit position. Also the condition of the oil as to its quantity and physical characteristics such as color may also be readily ascertained. Also the fuse may be inspected and the contact plates. The container provides for the escape of the exploded gases which escape may be effected without destroying the container or the switch. Also due to the manner of securing the cap and the core together, if either of these elements deteriorates to be ineffective or desirable to be changed, it is necessary to destroy the damaged element before it can be replaced, thus adding a safety factor to my switch.

The inner diameter of the insulating structure having the inside surface 3% is of slightly less diameter in line with the contacts than at right angles thereto. The increased diam eter in the transverse direction gives slightly more clearance for the contacts on the rotatable core when this is rotated out of electrical contact position.

Various changes may be made in the principles of my invention without departing from the spirit thereof as set forth in the description, drawings and claims.

I claim:

1. A switch having a vertically mounted container with vertical conducting contact strips on its inner surface and electrical connections through the walls of the container to said strips, an insulating core depending vertically in. the container and having pins mounted: for transverse movement, said pins.

having second 1 conducting-contact strips ;ver.-

ticallymounted thereon with; an. electrical connectionzbetween.the said latter strips, and

means extending outside of1the. containerto rotate the core .intoclosed or opencircuit position.

2. A switch as claimed; in. claim, 1,. the

connectingthe core andqthe cap to prevent separation thereof without breaking; either the core or-rthe cap.

3. A switch havinga pair ofxfixed contacts mounted in a first supportingstrueture with an electrical connection thereto, av comples mentary rotatable second supporting struc ture having electrical contacts .thereon-itoiengage with the first contacts,can operating means for the second supporting structure, connected to rotate said structure, the second supporting structure and the operating means being in two distinct parts and a connecting means requiring the destruction of the second supporting means or the operating means to disconnect same.

4. In a switch, a first insulating supporting structure having a plurality of fixed elec trical contacts thereon, with an electrical connection to said contacts, an insulating rotatable core having a second set of electrical contacts thereon, an operating cap connected to the core to rotate same and forming a separate element from the core, and means connecting the core and the cap requiring the destruction of one or the other to separate such core or cap.

5. A switch, comprising in combination a cup-like container to hold a liquid and having fixed conducting strips on the opposite inside walls with electrical connections there to, a cap rotatably mounted on the container, an insulating core fitted to the cap, said core having a second pair of conducting contacts mounted thereon for shifting transversely, a fuse in the container connecting the second contacts, and means preventing disconnection of the cap and the core unless one or the other is destroyed.

6. A switch as claimed in claim 5, the connection between the cap and core comprising a slidable dove-tailed connection with a dowel interfitting between the cap and the core, and means to retain the dowel in its operative posit-ion.

7 A switch, comprising in combination a cup-shaped container, means to support said container with its axis vertical, a pair of contact strips on opposite sides of the inside walls of the container, with electrical connections from each strip, a cap rotatably mounted on the container, a core connected to the cap by a dove-tailed connection and a dowel,

IOU

means to retain the dowel in operative position, whereby the cap and the core can only be separated by destruction of one or the other, a second pair of contact strips mounted on the core for a transverse movement With a fuse connecting said strips.

8. A switch, comprising in combination a holder adapted for attachment to asupporting structure, a cup-like container, interengaging means between the holder and the container having a Wedging fit, the container being insertable from the top of the holder, the container being adapted to contain a liquid, fixed contacts on the inside of the con- 15 tainer with electric connections thereto, a core rotatably mounted in the container, the core having a pair of contacts electrically connected to engage the fixed contacts on the container.

20 In testimony whereof I have signed my name to this specification.

L. J. SJOBERG.

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